Bicycle gearshift

Abstract

The disclosed bicycle gearshift ( 20 ) includes a support member ( 22 ) configured for mounting on a bicycle frame, a driving member ( 24 ) for driving of a bicycle chain, and at least one articulation arm ( 28 ) to movably connect the driving member ( 24 ) to the support member ( 22 ). The articulation arm ( 28 ) is connected to at least one portion of the support member ( 22 ) and the driving member ( 24 ) so that it can rotate about a respective rotational axis ( 30 a ) through at least one respective connecting pin ( 40 a ) extending along the rotational axis ( 30 a ). At least one first rolling element ( 54 ) is operatively arranged in the radial direction between the connecting pin ( 40 a ), one of the articulation arms ( 28 ), the portion of the support member ( 22 ), and the driving member ( 24 ).

1 . A bicycle gearshift ( 20 ), comprising a support member ( 22 ) configured to be mounted on a bicycle frame, a driving member ( 24 ) that drives a bicycle chain, and at least one articulation arm ( 26 ,  28 ) to movably connect said driving member ( 24 ) to said support member ( 22 ), said at least one articulation arm ( 26 ,  28 ) being connected to at least one portion of said support member ( 22 ) and said driving member ( 24 ) so that it rotates around a respective rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ) through at least one respective connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) extending along said rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ), the gearshift comprising at least one first rolling element ( 57 ) operatively arranged in the radial direction between said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ), one of said at least one articulation arms ( 26 ,  28 ) and said at least one portion of said support member ( 22 ), or said driving member ( 24 ). 
   
   
       2 . The gearshift ( 20 ) of  claim 1 , wherein said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) is associated with said at least one portion of said support member ( 22 ) or said driving member ( 24 ), and said at least one first rolling element ( 57 ) is arranged between said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and said at least one articulation arm ( 26 ,  28 ). 
   
   
       3 . The gearshift ( 20 ) of  claim 2 , wherein said at least one connecting pin ( 37 ) is formed as one piece with said at least one portion of said support member ( 22 ) or said driving member. 
   
   
       4 . The gearshift ( 20 ) of  claim 2 , wherein said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) is removably associated with said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       5 . The gearshift ( 20 ) of  claim 1 , wherein said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) is associated with said at least one articulation arm ( 26 ,  28 ), and said at least one first rolling element ( 57 ) is arranged between said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and said at least one portion of said support member or said driving member. 
   
   
       6 . The gearshift ( 20 ) of  claim 5 , wherein said at least one connecting pin is formed as one piece with said at least one articulation arm. 
   
   
       7 . The gearshift ( 20 ) of  claim 5 , wherein said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) is removably associated with said at least one articulation arm ( 26 ,  28 ). 
   
   
       8 . The gearshift ( 20 ) of  claim 1 , wherein said at least one articulation arm ( 26 ,  28 ), and at least one portion of said support member ( 22 ) or said driving member ( 24 ) rest directly on one another in the axial direction. 
   
   
       9 . The gearshift ( 20 ) of  claim 1 , wherein said at least one articulation arm ( 26 ,  28 ) and at least one portion of said support member ( 22 ) or said driving member ( 24 ) rest on one another in the axial direction through the interposition of at least one second rolling element ( 63 ). 
   
   
       10 . The gearshift ( 20 ) of  claim 1 , further comprising at least one setting device ( 51 ) that exerts a preloading force in the axial direction on said at least one articulation arm ( 26 ,  28 ), said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       11 . The gearshift ( 20 ) of  claim 1 , further comprising at least one elastic element ( 59 ,  60 ,  160 ) operatively arranged between said at least one articulation arm ( 26 ,  28 ), said at least one portion of said support member ( 22 ), or said driving member ( 24 ), to exert a biasing force in the axial direction on said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       12 . The gearshift ( 20 ) of  claim 11 , wherein said at least one elastic element ( 59 ,  60 ,  160 ) is arranged between said at least one first rolling element ( 57 ), said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       13 . The gearshift ( 20 ) of  claim 9 , further comprising at least one setting device ( 51 ) that exerts a preloading force in the axial direction on said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ) or said driving member ( 24 ), further comprising at least one elastic element ( 59 ,  60 ,  160 ) operatively arranged between said at least one articulation arm ( 26 ,  28 ), said at least one portion of said support member ( 22 ), or said driving member ( 24 ), to exert a biasing force in the axial direction on said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ), or said driving member ( 24 ), wherein said at least one elastic element ( 60 ) is arranged between said at least one first rolling element ( 57 ) and said at least one second rolling element ( 63 ) and between said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       14 . The gearshift ( 20 ) of  claim 9  further comprising at least one elastic element ( 59 ,  60 ,  160 ) operatively arranged between said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ), or said driving member ( 24 ), to exert a biasing force in the axial direction on said at least one articulation arm ( 26 ,  28 ), and said at least one portion of said support member ( 22 ) or said driving member ( 24 ), wherein said at least one elastic element ( 160 ) is also arranged between said at least one second rolling element ( 63 ) and said at least one articulation arm ( 26 ,  28 ) and said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       15 . The gearshift ( 20 ) of  claim 11 , wherein said at least one elastic element ( 60 ,  160 ) comprises a disc spring. 
   
   
       16 . The gearshift ( 20 ) of  claim 2 , wherein said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) is rigidly fixed to said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       17 . The gearshift ( 20 ) of  claim 16 , wherein said at least one connecting pin ( 40   a ,  41   b ) is screwed into at least one threaded cavity of said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       18 . The gearshift ( 20 ) of  claim 16 , wherein said at least one connecting pin is screwed into at least one threaded cavity ( 47   c ) of at least one insert ( 47 ,  147 ) associated with said at least one portion of said support member ( 22 ) or said driving member ( 28 ). 
   
   
       19 . The gearshift ( 20 ) of  claim 1 , wherein said at least one first rolling element ( 57 ) is in a radial bearing ( 54 ). 
   
   
       20 . The gearshift ( 20 ) of  claim 19 , wherein said radial bearing ( 54 ) comprises an inner ring ( 55 ) fitted onto said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and an outer ring ( 56 ) associated with the inside of at least one cavity ( 52 ) of said at least one articulation arm ( 26 ,  28 ) or of said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       21 . The gearshift ( 20 ) of  claim 20 , wherein said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) comprises a head ( 51 ) in axial abutment with said inner ring ( 55 ) of said radial bearing ( 54 ). 
   
   
       22 . The gearshift ( 20 ) of  claim 9 , wherein said at least one second rolling element ( 63 ) is comprised in an axial bearing ( 62 ). 
   
   
       23 . The gearshift ( 20 ) of  claim 22 , wherein said axial bearing ( 62 ) is operatively arranged between the outer ring ( 56 ) of said radial bearing ( 54 ) and one of said at least one articulation arms ( 26 ,  28 ) and said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       24 . The gearshift ( 20 ) of  claim 22 , wherein said axial bearing ( 62 ) has a first ring ( 64 ) adjacent to the radial bearing ( 54 ) mounted with clearance on said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and a second ring ( 66 ) opposite said first ring ( 64 ) mounted with clearance on said at least one articulation arm ( 26 ,  28 ) or on said at least one portion of said support member ( 22 ) or said driving member ( 24 ). 
   
   
       25 . The gearshift ( 20 ) of  claim 9 , wherein said at least one first rolling element ( 57 ) and said at least one second rolling element ( 63 ) are comprised in a single bearing ( 154 ) having a double row of rolling elements ( 157 ). 
   
   
       26 . The gearshift ( 20 ) of  claim 1 , further comprising first circumferential pathways ( 90 ) defined in said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and in said at least one articulation arm ( 26 ,  28 ) or at least one portion of said support member ( 22 ) or driving member ( 24 ), to permit rolling of said at least one first rolling element ( 57 ). 
   
   
       27 . The gearshift ( 20 ) of  claim 1 , further comprising second circumferential pathways ( 92 ) defined in said at least one articulation arm ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and in said at least one portion of said support member ( 22 ) or driving member ( 24 ), to permit rolling of at least one second rolling element ( 63 ). 
   
   
       28 . The gearshift ( 20 ) of  claim 1 , further comprising two articulation arms ( 26 ,  28 ), wherein said at least one first rolling element ( 57 ) is coupled with one of the two articulation arms ( 28 ) that is closest to a bicycle frame when the gearshift ( 20 ) is associated with the frame. 
   
   
       29 . The gearshift ( 20 ) of  claim 28 , wherein said at least one first rolling element ( 57 ) is coupled with said articulation arm ( 28 ) at a portion of said articulation arm ( 28 ) which is axially farthest away from a driving portion ( 25 ) of said driving member ( 24 ). 
   
   
       30 . The gearshift ( 20 ) of  claim 1 , wherein said gearshift is a motorized gearshift ( 20 ). 
   
   
       31 . The gearshift ( 20 ) of  claim 1 , wherein said gearshift is a manually actuated gearshift. 
   
   
       32 . A bicycle comprising a gearshift ( 20 ), the gearshift comprising a support member ( 22 ) configured to be mounted on a bicycle frame, a driving member ( 24 ) that drives a bicycle chain and at least one articulation arm ( 26 ,  28 ) to movably connect said driving member ( 24 ) to said support member ( 22 ), said at least one articulation arm ( 26 ,  28 ) being connected to at least one portion of said support member ( 22 ) and said driving member ( 24 ) so that it rotates around a respective rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ) through at least one respective connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) extending along said rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ), the gearshift comprising at least one first rolling element ( 57 ) operatively arranged in the radial direction between said at least one connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ), one of said at least one articulation arms ( 26 ,  28 ) and said at least one portion of said support member ( 22 ), or said driving member ( 24 ). 
   
   
       33 . A shifter ( 20 ), for controlling the position of a bicycle chain, the shifter comprising:
 a support member ( 22 ) configured to be mounted on a bicycle frame about a chain;   a driving member ( 24 );   an articulation arm ( 26 ,  28 ) that movably connects the driving member ( 24 ) to the support member ( 22 );   a plurality of connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) that connect the support member ( 22 ), driving member ( 24 ), and the articulation arm ( 26 ,  28 ); and   at least one first rolling element ( 57 ) mounted about a rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ) at a radially outer position with respect to a connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ).   
   
   
       34 . A bicycle gearshift ( 20 ), comprising:
 a plurality of members ( 22 ,  24 ,  26 ,  28 ) attached by connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) associated with respective rotational axes ( 30   a ,  30   b ,  30   c ,  30   d ) to form an articulated quadrilateral; and   a rolling element ( 57 ) mounted at a radially outer position with respect to a connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ).   
   
   
       35 . A gearshift ( 20 ), for selecting the position of a bicycle chain, the gearshift comprising:
 a support member ( 22 ) mountable on a bicycle frame;   a driving member ( 24 );   articulation arms ( 26 ,  28 );   connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) that form the support member ( 22 ), the driving member ( 24 ) and the articulation arms ( 26 ,  28 ) into a quadrilateral, such that the driving member ( 24 ) rotates around a respective rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ); and   first and second rolling elements ( 57 ,  62 ) arranged in the radial direction between at least one of the connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and a selected one of the articulation arms ( 26 ,  28 ), support member ( 22 ) and driving member ( 24 ).   
   
   
       36 . A bicycle gearshift ( 20 ), comprising:
 a support member ( 22 ) configured to be mounted on a bicycle frame;   a driving member ( 24 ) that drives a bicycle chain; and   at least one articulation arm ( 26 ,  28 ) to movably connect the driving member ( 24 ) to the support member ( 22 );   wherein the at least one articulation arm ( 26 ,  28 ) is connected to at least one portion of each of the support member ( 22 ) and the driving member ( 24 ) so that it rotates around respective rotational axes ( 30   a ,  30   b ,  30   c ,  30   d ) through at least one respective connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) extending along the rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ); and   the at least one articulation arm ( 26 ,  28 ) and at least one portion of the support member ( 22 ) or the driving member rest on one another in the axial direction through the interposition of at least one radial bearing ( 54 ) comprising a first rolling element ( 57 ) and at least one axial bearing ( 62 ) comprising a second rolling element ( 63 );   the bearings ( 54 ,  62 ) being mounted about the rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ), at radially outer positions with respect to a connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ).   
   
   
       37 . A bicycle gearshift ( 20 ), comprising:
 a support member ( 22 ) configured to be mounted on a bicycle frame;   a driving member ( 24 ) that drives a bicycle chain; and   at least one articulation arm ( 26 ,  28 ) that movably connects the driving member ( 24 ) to the support member ( 22 );   wherein the at least one articulation arm ( 26 ,  28 ) is connected to at least one portion of the support member ( 22 ) and the driving member ( 24 ) so that it rotates around a respective rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ) through at least one respective connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) extending along the rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ); and   the at least one articulation arm ( 26 ,  28 ) and at least one portion of the support member ( 22 ) or the driving member rest on one another in the axial direction through the interposition of at least one radial bearing ( 54 ) comprising a first rolling element ( 57 ), at least one axial bearing ( 62 ) comprising a second rolling element ( 63 ), and at least one elastic element ( 59 ,  60 ,  160 ) interposed between the bearings ( 54 ,  62 );   the bearings ( 54 ,  62 ) and elastic element ( 59 ,  60 ,  160 ) each being mounted about the rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ), at radially outer positions with respect to a connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ).   
   
   
       38 . A bicycle gearshift ( 20 ) comprising:
 a support member ( 22 ) configured to be mounted on a bicycle frame;   a driving member ( 24 ) that drives a bicycle chain; and   first and second articulation arms ( 26 ,  28 ) located at different distances from the bicycle frame that are pivotally connected to at least one portion of each of the support member ( 22 ) and the driving member ( 24 ) about respective rotational axes ( 30   a ,  30   b ,  30   c ,  30   d ) to form an articulated quadrilateral arrangement; and   the second articulation arm ( 28 ) and at least one portion of the support member ( 22 ) or the driving member ( 24 ) are axially stacked through the interposition of at least one radial bearing ( 54 ) comprising a first rolling element ( 57 ) and at least one axial bearing ( 62 ) comprising a second rolling element ( 63 ), each of the bearings being associated a portion of the second articulation arm ( 28 );   the bearings ( 54 ,  62 ) are mounted about the rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ), at radially outer positions with respect to a connecting pin ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ).   
   
   
       39 . A motorized shifter ( 20 ), for controlling the position of a bicycle chain, the shifter comprising:
 a support member ( 22 ) configured to be mounted on a bicycle frame about a chain and shaped to house a worm screw ( 32 ) actuated by an electric motor ( 35 );   a driving member ( 24 );   an articulation arm ( 26 ,  28 ) that connects the driving member ( 24 ) to the support member ( 22 ) and engages the worm screw ( 32 );   a plurality of connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) that connect the support member ( 22 ), driving member ( 24 ), and the articulation arm ( 26 ,  28 ) to form an articulated quadrilateral; and   at least one rolling element ( 57 ) mounted about a rotational axis ( 30   a ,  30   b ,  30   c ,  30   d ).   
   
   
       40 . A motorized shifter for a bicycle, the shifter ( 20 ) comprising:
 a support member ( 22 ) configured to mount on a bicycle frame adjacent to a bicycle chain;   a drive member ( 24 );   articulation arms ( 26 ,  28 ), at least one of which has an extension ( 27 );   a plurality of connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) that join the support member ( 22 ), drive member ( 24 ) and articulation arms ( 26 ,  28 ) into an articulated quadrilateral that houses a motor driven worm screw ( 32 ) that engages the extension ( 27 ); and   at least one rolling element ( 57 ) positioned between a selected one of the connecting pins ( 37 ,  38 ,  40   a ,  40   b ,  41   a ,  41   b ) and a selected one of the articulated quadrilateral elements ( 22 ,  24 ,  26 ,  28 ).